NASA’s page on wildfires might be worth saving or screenshotting before it’s taken down.
Media doing a particularly poor job of making the wildfire, Air Quality, Climate connection.
NASA’s Terra and Aqua satellites detect active wildfires twice each day. Scientists studied this data over a 21-year span and found that extreme wildfires have become more frequent, more intense, and larger. The largest increase in extreme fire behavior was in the temperate conifer forests of the Western U.S. and the boreal forests of northern North America and Russia. Warmer nighttime temperatures are a major contributing factor, allowing fire activity to persist overnight.
Here we identify energetically extreme wildfire events by calculating daily clusters of summed fire radiative power using 21 years of satellite data, revealing that the frequency of extreme events (≥99.99th percentile) increased by 2.2-fold from 2003 to 2023, with the last 7 years including the 6 most extreme. Although the total area burned on Earth may be declining, our study highlights that fire behaviour is worsening in several regions—particularly the boreal and temperate conifer biomes—with substantial implications for carbon storage and human exposure to wildfire disasters.
Most fires on Earth are small, ignited by humans, and not remarkably damaging. Indeed, fire plays a crucial role in the health of most fire-adapted ecosystems. It has been widely reported that the area burned globally has decreased this century, but this trend is mostly driven by declines in low-intensity fires in African grasslands and savannas. Globally, average fire intensity has also been decreasing this century (with some regional increases), but burn severity, an ecological measure of a fire’s immediate effects (for example, biomass loss and mortality), is increasing in more regions than it is decreasing.
In contrast to the majority of fires, energetically extreme wildfires are associated with extreme ecological, social and economic consequences, including emitting vast quantities of smoke and greenhouse gases that threaten to further accelerate warming.
Despite their importance, there remains no systematic evidence of temporal trends in extreme wildfires. In a study of energetically extreme wildfires, no temporal trend was revealed, potentially because of the relatively short satellite record used in the study (12 years, 2002–2013).
Likewise, global trends have not yet been observed for pyrocumulonimbus events (storms triggered by extremely intense wildfires).
A lack of trends is unexpected because warming temperatures and increasing vapour pressure deficit are drying fuels and worsening fire weather across most of the Earth. Climate change has already caused fire weather to depart from its historical variability across ~20% of burnable land area globally, and recent extremely destructive wildfire seasons have occurred in the Amazon, Australia, Canada, Chile, Portugal, Indonesia, Siberia and the western United States. While the notion of increasingly dangerous wildfires pervades the media,such trends have not been systematically shown. (until now)
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While higher temperature is the main driver of the increased fire extreme probability, shifts in precipitation, relative humidity, and/or wind speed substantially modulated fire changes across many regions. Mainly because of warming, the probability of extreme fires attributable to human-induced climate change increased by 5.2%/decade globally over 2002–2015, in line with an acceleration of the climate-driven enhancement of fire extremes over the last decades that may continue in the near future. These findings highlight the urgent need for sustainable fire management strategies.